IB Computer Science Paper 1 Topic 1

Five advantages of SAAS

* Lower initial costs
* Scalability and flexibility
* Automatic updates and maintenance
* Accessibility from anywhere with internet connection
* Easy integration with other software systems

Five disadvantages of SAAS

* Dependence on internet connectivity
* Limited customization options
* Security concerns with sensitive data
* Potential for service disruptions or downtime
* Difficulty in migrating to a different platform or vendor

T in TELOS?

Technical feasibility - is the existing technology sufficient to implement the proposed system?

E in TELOS?

Economic - is the proposed system cost effective?

L in TELOS?

L in TELOS stands for "Legal feasibility." It refers to the ability of a proposed project to comply with legal requirements and regulations

O in TELOS?

Operational - are the existing organisational practices and procedures sufficient to support the maintenance and operation of the new system?

S in TELOS?

Schedule - how long will it take?

What is changeover?

The process of putting the new system online and retiring the old one

What are the different types of changeover?

* Parallel Changeover
* Direct Changeover
* Phased Changeover
* Pilot Changeover

Advantages / disadvantages of parallel changeover

Advantages:

* Minimal disruption to operations
* Lower risk of system failure
* Easier to revert back to previous system if needed

Disadvantages:

* Longer implementation time
* Higher cost due to running two systems simultaneously
* Potential for confusion and errors during transition period

Advantages / disadvantages of direct changeover

Advantages:

* Quick implementation
* Cost efficient

Disadvantages:

* High risk of failure
* No fallback option

What is a merger?

A merger is a business transaction where two or more companies combine to form a single entity.

Issues with maintaining legacy systems

* Maintaining old / outdated computer systems
* May be compatibility issues with the old programming language
* Lack of organisation / documentation - might make it hard to understand
* Will be hard to find employees that can understand / manage it - inefficient and costly

Compatibility issues during mergers

* Software incompatibility - both companies might use differing software
* Language differences
* Legacy systems - old tech that still serves its purpose so is still in use, but cannot be updated to newer systems

Problems with data migration

* Loss of data
* Data corruption
* Incomplete data transfer
* Incompatible data formats
* Lack of proper testing
* User resistance to change

Alpha testing

Carried out internally, pre-release, at the developer’s site

Beta testing

Testing prior to release to see if it works properly performed by end users

Stages of the data migration cycle

Plan, migrate, validate

Causes of data loss

* Natural disasters
* Power loss
* Data corruption
* Malware like viruses

Methods for avoiding data loss

* Create regular backups
* Install a firewall
* Offsite storage of data

Methods of obtaining information from shareholders

* Unstructured / structured interviews
* Closed / open questionnaires
* Direct observation

Direct observation

Pros

* Allows for the system to be studied naturally
* More reliable than questionnaires, as you can see what people do rather than what they say they do
* Provides a better understanding of how the computer system works

Cons

* May change the behaviour of the people being observed
* Time consuming

Interviews

Pros

* More complete / in depth data can be given
* Clarifications can be given for unsure details

Cons

* Time consuming

Questionnaires

Pros

* A lot of people can be reached in a short amount of time
* Easy to analyse / perform statistical analysis

Cons

* A lot of people might not respond

Purpose of creating a prototype

* Allow stakeholders to get an idea of how the finished product would work so they can suggest improvements

Reasons for providing software updates

* To patch any bugs / vulnerabilities
* To provide improved / new functionality
* To generate income for the company by staying ahead of other companies
* To ensure compatibility with other updated technologies

How developers could let users know that updates are available

* Send an email with a link to the update

Usability

Making computer systems easier to use, marching them closely with user requirements and needs

Accesibility

The potential of a service, product or device to match as many individuals as possibel

Potential usability issues

* Small screens
* Small keyboard
* Low battery life
* Touch screen - low tactile feedback
* Fragility
* Low quality speakers

Methods for providing user documentation

* Manuals
* Email support
* FAQs
* Live chat sessions

Importance of testing

* to test :)
* To make sure the system operates in line with user requirements
* To enable early discovery of errors - saves time

Techniques to gather the information needed to find a suitable solution for an updated system

* Examine current systems to compare the current system against possible requirements to identify missing features
* Examine competing products to compare own systems to enable decisions on features to add

Consequences of not involving all stakeholders in product development

* user dissatisfaction because the system does not meet user requirements
* beef in office -- exclusion from xmas party
* developers not being paid for final product as the business owner requests are not evident in the final product

Why programs written in higher level languages must be translated into machine code

* So that the computer can execute the code, as it only understands machine language